The gastrointestinal (GI) tract comprises the esophagus, the stomach, the small intestine, the large intestine, the colon, and the anal sphincter and is generally described as having a tract axis. Like other organs of the body, most notably the heart, these organs naturally undergo regular rhythmic contractions. In particular these contractions take the form of peristaltic contractions and are essential for the movement of food through each of the respective organs. Like the heart, these contractions are the result of regular rhythmic electrical depolarizations of the underlying tissue.
Irregular contractions of any or all of the organs of the GI tract can have negative or undesirable impacts on an individual. For example, gastroparesis is an adverse medical condition in which normal gastric motor function is impaired. Gastroparesis results in delayed gastric emptying as the stomach takes too long to empty its contents. Typically, gastroparesis results when muscles within the stomach or intestines are not working normally, and movement of food through the stomach slows or stops. Patients with gastroparesis typically exhibit symptoms of nausea and vomiting, as well as gastric discomfort such as bloating or a premature or extended sensation of fullness, i.e., satiety. The symptoms of gastroparesis are the result of reduced gastric motility. Gastroparesis generally causes reduced food intake and subsequent weight loss, and can adversely affect patient health.
Electrical stimulation of the gastrointestinal tract has been used to treat symptoms of gastroparesis. For example, electrical stimulation of the gastrointestinal tract, and especially the stomach, is effective in suppressing symptoms of nausea and vomiting secondary to diabetic or idiopathic gastroparesis. Typically, electrical stimulation involves the use of electrodes implanted in the muscle wall of the target organ, e.g., the muscle wall of the stomach in the case of gastric stimulation. The electrodes are electrically coupled to an implanted or external pulse generator via implanted or percutaneous leads. The pulse generator delivers a stimulation waveform via the leads and electrodes. An example of an implanted pulse generator suitable for gastric stimulation is the ITREL 3, commercially available from Medtronic, Inc., of Minneapolis, Minn.
One method of diagnosing and/or treating various conditions of the GI tract includes electrical stimulation of some portion of the GI tract. Devices for stimulating and/or sensing the electrical activity of some portion of the GI tract can be found in the prior art.
One such device, which combines sensing and stimulating actions, can be found in commonly assigned U.S. Pat. No. 6,754,536, the disclosure of which is incorporated by reference herein. Commonly assigned U.S. patent application Ser. No. 10/801,230, filed Mar. 16, 2004 entitled “Intra-luminal devices for gastrointestinal electrical stimulation” discloses another device that can be used to stimulate and/or sense electrical activity within the GI tract. Modifying and/or enhancing their attachment mechanism(s) could improve devices such as these and others for some applications.
The present invention provides an alternative method and system for attaching devices to the inside of the GI tract